Python 3 compatibility for parse_elfnote.py.

Test: Used with python 2.7 and python 3.6
Bug: None
Change-Id: I2d58a67467b69d55c9f46753e72ccd639d2347be

1 files changed, 18 insertions, 14 deletions

diff --git a/parse_elfnote.py b/parse_elfnote.py
index f85fc8a35..74a61fbbf 100755
--- a/parse_elfnote.py
+++ b/parse_elfnote.py
@@ -32,10 +32,6 @@ import struct
 import subprocess
 import sys
 
-try:
-    from StringIO import StringIO
-except ImportError:
-    from io import StringIO
 
 SEC_NAME = '.note.android.ident'
 NDK_RESERVED_SIZE = 64
@@ -54,21 +50,27 @@ def round_up_to_nearest(val, step):
 
 class StructParser(object):
     def __init__(self, buf):
-        self._sio = StringIO(buf)
+        self.buf = buf
+        self.pos = 0
 
     @property
-    def _remaining(self):
-        return self._sio.len - self._sio.pos
+    def remaining(self):
+        return len(self.buf) - self.pos
 
     @property
     def empty(self):
-        return self._remaining == 0
+        return self.remaining == 0
+
+    def read(self, read_len):
+        buf = self.buf[self.pos:read_len + self.pos]
+        self.pos += read_len
+        return buf
 
     def read_struct(self, fmt, kind):
         fmt = struct.Struct(fmt)
-        if self._remaining < fmt.size:
+        if self.remaining < fmt.size:
             sys.exit('error: {} was truncated'.format(kind))
-        return fmt.unpack(self._sio.read(fmt.size))
+        return fmt.unpack(self.read(fmt.size))
 
 
 def iterate_notes(sec_data):
@@ -82,7 +84,7 @@ def iterate_notes(sec_data):
             'note body')
         name = name[:namesz]
         if len(name) > 0:
-            if name[-1:] == '\0':
+            if name[-1:] == b'\0':
                 name = name[:-1]
             else:
                 logger().warning('note name %s isn\'t NUL-terminated', name)
@@ -97,9 +99,11 @@ def dump_android_ident_note(note):
         return
     # Binaries generated by NDK r14 and later have these extra fields. Platform
     # binaries and binaries generated by older NDKs don't.
-    (ndk_version, ndk_build_number) = note.read_struct(
+    ndk_version, ndk_build_number = note.read_struct(
         '{}s{}s'.format(NDK_RESERVED_SIZE, NDK_RESERVED_SIZE),
         'note descriptor')
+    ndk_version = ndk_version.decode('utf-8')
+    ndk_build_number = ndk_build_number.decode('utf-8')
     print('ABI_NDK_VERSION: {}'.format(ndk_version.rstrip('\0')))
     print('ABI_NDK_BUILD_NUMBER: {}'.format(ndk_build_number.rstrip('\0')))
     if not note.empty:
@@ -110,7 +114,7 @@ def dump_android_ident_note(note):
 def get_section_pos(sec_name, file_path):
     cmd = ['readelf', '--sections', '-W', file_path]
     output = subprocess.check_output(cmd)
-    lines = output.splitlines()
+    lines = output.decode('utf-8').splitlines()
     for line in lines:
         logger().debug('Checking line for "%s": %s', sec_name, line)
         # Looking for a line like the following (all whitespace of unknown
@@ -168,7 +172,7 @@ def main():
         if len(sec_data) == 0:
             logger().warning('%s section is empty', SEC_NAME)
         for (name, kind, desc) in iterate_notes(sec_data):
-            if (name, kind) == ('Android', 1):
+            if (name, kind) == (b'Android', 1):
                 dump_android_ident_note(desc)
             else:
                 logger().warning('unrecognized note (name %s, type %d)',